A method for purifying phosphine-based compounds

Abstract

This invention discloses a method for purifying phosphine-based compounds, belonging to the field of organic synthesis technology. The organophosphine R... 1 R 2 R 3 P impurities are caused by organophosphorus R 1 R 2 R 3 The composition consists of P and impurities, the impurities including R. 1 R 2 R 3 PO and R 1 R 2 R 3 One or any combination of two of the PS; where R 1 R 2 and R 3 R is independently selected from aromatic or aliphatic substituents. 1 R 2 and R 3 At least one of them is an aromatic substituent; the method includes the following steps: under an inert gas or nitrogen atmosphere, to the organophosphorus R 1 R 2 R 3 P is impurity with the addition of excess metal X and organophosphorus R. 1 R 2 R 3 Impurity P reacts completely with metal X in a nonpolar hydrocarbon solvent. After the reaction, the reaction products are separated, and the solvent and R are removed by rotary evaporation under reduced pressure. 3 The compound was obtained as an organophosphorus R. 1 R 2 R 3 P. It can effectively remove phosphonium oxides and phosphonium sulfur compounds from phosphonium-based compounds, effectively purifying impurities in phosphonium-based compounds. This method is simple, easy to operate, safe and controllable, and easy to scale up for industrial production.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and more specifically, to a method for purifying phosphine-based compounds. Background Technology

[0002] Organophosphorus compounds (R3Ps) are important fine chemical intermediates, used as accelerators, flame retardants, heat stabilizers, rubber antioxidants, and antistatic agents. They are widely used in petrochemical, pharmaceutical, dye, polymer materials, and analytical fields. Triphenylphosphine, for example, is also an important chemical reagent, widely used in various important chemical reactions such as the Wittig, Staudinger, Mitsunobu, and Appel reactions.

[0003] Organophosphorus compounds (R3P) are readily oxidized to R3PO in air. During the manufacturing process, R3P may contain small amounts of R3PO or R3PS. Industrially and in laboratories, these impurities are typically removed using common organic synthesis purification methods, such as silica gel column chromatography, recrystallization, or distillation. However, silica gel column chromatography and recrystallization generally require large amounts of solvent, and distillation is difficult to use to purify compounds like Ph3P due to its high boiling point.

[0004] To address the aforementioned technical problems, this invention focuses on developing a simple method for purifying phosphine-based compounds. Summary of the Invention

[0005] 1. Technical problems to be solved

[0006] To address the problems existing in the prior art, the present invention aims to provide a method for purifying phosphine-based compounds. This method can effectively remove phosphine oxide and phosphine sulfur impurities from phosphine-based compounds, effectively purifying impurities in phosphine-based compounds. The method is simple, easy to operate, safe and controllable, and easy to scale up for industrial production.

[0007] 2. Technical Solution

[0008] To solve the above problems, the present invention adopts the following technical solution.

[0009] A method for purifying phosphine-based compounds, wherein the organophosphine R 1 R 2 R 3 P impurities are caused by organophosphorus R 1 R 2 R 3 The composition consists of P and impurities, the impurities including R. 1 R 2 R 3P0 and R 1 R 2 R 3 One or any combination of two of the PS; where R 1 R 2 and R 3 R is independently selected from aromatic or aliphatic substituents. 1 R 2 and R 3 At least one of them is an aromatic substituent, R 1 R 2 and R 3 The steps can be the same or different; the method includes the following steps:

[0010] Organophosphorus R 1 R 2 R 3 The reaction formula for purifying impurity P is:

[0011]

[0012] R 1 R 2 R 3 The reaction equation for the reaction between PS and metal X in a nonpolar hydrocarbon solvent is as follows:

[0013] R 1 R 2 R 3 The reaction equation for the reaction of PO with metallic X in a nonpolar hydrocarbon solvent is as follows:

[0014]

[0015] Step 1: Under an inert gas or nitrogen atmosphere, apply organophosphorus R... 1 R 2 R 3 P is impurity with the addition of excess metal X and organophosphorus R. 1 R 2 R 3 Impurity P reacts fully with metal X under nonpolar hydrocarbon solvent conditions;

[0016] The metal X is selected from one or any mixture of Li, Na and K;

[0017] The reaction temperature is 0-250℃;

[0018] Step 2: After the reaction is complete, use organophosphorus R 1 R 2 R 3 P is soluble in organic solvents but insoluble in water, R 1 R 2Based on the properties that POX is soluble in water but insoluble in non-ether organic solvents, and X₂S is soluble in water but insoluble in organic solvents, and that metallic X is soluble in water but insoluble in organic solvents, the reaction products were separated by rotary evaporation under reduced pressure to remove the solvent and R. 3 The compound was obtained as an organophosphorus R. 1 R 2 R 3 P.

[0019] Furthermore, the molar ratio of the metal to the impurity is 0.1-5:1.

[0020] Furthermore, the molar ratio of the metal to the impurity is 1-2:1.

[0021] Furthermore, the reaction temperature is 60-180℃.

[0022] Furthermore, in the method, when the organophosphorus R... 1 R 2 R 3 Before adding metal to impurities P, organophosphorus R 1 R 2 R 3 The impurity P first dissolves in a nonpolar hydrocarbon solvent.

[0023] Nonpolar solvents are defined as solvents with low dielectric constants, also known as inert solvents. These solvents neither undergo proton self-transfer reactions nor solvate with solutes. They are mostly saturated hydrocarbons or compounds such as benzene.

[0024] Furthermore, the organophosphorus R 1 R 2 R 3 P does not react with metals under solvent-free or nonpolar hydrocarbon solvent conditions.

[0025] Furthermore, the organophosphorus R 1 R 2 R 3 P does not react with the nonpolar hydrocarbon solvent.

[0026] Furthermore, the R 1 R 2 R 3 PS reacts with the metal to generate R. 1 R 2 R 3 p and divalent sulfide metals insoluble in organic solvents, the organophosphine R 1 R 2 R 3 P does not react with the metal.

[0027] Furthermore, nonpolar hydrocarbon solvents with R 1 R2 R 3 The weight ratio of impurities P is 0.5-20:1.

[0028] Furthermore, nonpolar hydrocarbon solvents with R 1 R 2 R 3 The weight ratio of impurities P is 2-5:1.

[0029] Furthermore, the nonpolar hydrocarbon solvent is selected from one or any mixture of alkanes or aromatics.

[0030] Furthermore, the nonpolar hydrocarbon solvent is selected from one or any mixture of several of the following: n-hexane, n-heptane, polyethylene, polypropylene, benzene, toluene, ethylbenzene, xylene, and trimethylbenzene.

[0031] Furthermore, R 1 R 2 and R 3 Can be selected independently from C1-C 20 Straight-chain or branched alkyl or alkenyl groups, C3-C 20 cycloalkyl, C7-C 20 Aryl groups, C6-C 20 aryl and C2-C 20 Heterocyclic groups.

[0032] Furthermore, R 1 R 2 and R 3 The compounds are independently selected from phenyl groups with C1-C6 long-chain or branched alkyl groups, heterocyclic aromatics containing N, O, and S atoms, and C1-C6... 20 Long-chain or branched alkyl groups.

[0033] Furthermore, the metal is selected from sodium.

[0034] Furthermore, the R 1 R 2 R 3 PO is Ph3PO, R 1 R 2 R 3 PS stands for Ph3PS, R 1 R 2 R 3 P is Ph3P.

[0035] Furthermore, the nonpolar hydrocarbon solvent is one or any mixture of toluene, ethylbenzene, benzene, xylene, and trimethylbenzene.

[0036] The present invention will be further described below:

[0037] This invention utilizes the reaction of phosphine sulfide compound R3PS in phosphine-based compound R3P with metal X under nonpolar hydrocarbon solvent conditions, wherein phosphine sulfide compound R3PS reacts fully with the metal to generate divalent metal sulfide and R3P.

[0038] No byproducts are produced in this process. The phosphine compound R3P does not react with metals or with nonpolar hydrocarbon solvents under nonpolar hydrocarbon solvent conditions. The generated phosphine compound R3P is insoluble in water. The divalent metal sulfide is insoluble in organic solvents but readily soluble in water.

[0039] The present invention will be further described below:

[0040] Phosphine sulfur compounds R 1 R 2 R 3 PS reacts with a metal reducing agent X in a nonpolar hydrocarbon solvent under an inert gas or nitrogen atmosphere to produce an organophosphorus compound R. 1 R 2 R 3 P and divalent sulfide metals.

[0041] The reducing agents, namely Li, Na, and K, as well as the divalent metal sulfides produced in the reaction, are all insoluble in organic solvents. Phosphine sulfide compounds R... 1 R 2 R 3 PS and the organophosphine R generated by the reaction 1 R 2 R 3 P is soluble in organic solvents.

[0042] After the reaction is complete, the following separation and purification methods can be used to obtain pure organophosphorus R. 1 R 2 R 3 P; The separation and purification method is as follows:

[0043] Phosphine sulfur compounds R 1 R 2 R 3 PS reacts with a metal reducing agent under nonpolar hydrocarbon solvent conditions. After the reaction is complete, pure organophosphorus R is obtained by the following separation and purification method. 1 R 2 R 3 P; due to organophosphorus R 1 R 2 R 3 P is soluble in nonpolar hydrocarbon solvents, while divalent metal sulfides are insoluble in nonpolar hydrocarbon solvents. After the reaction is complete, the divalent metal sulfides are separated by filtration to obtain the organic phase. The nonpolar hydrocarbon solvent is then removed under reduced pressure to obtain the organophosphine R. 1 R2 R 3 P.

[0044] Pure organophosphorus R can also be obtained by the following separation and purification methods. 1 R 2 R 3 P; The separation and purification method is as follows: Phosphine sulfide compounds R 1 R 2 R 3 PS reacts with a metal reducing agent under nonpolar hydrocarbon solvent conditions. After the reaction is complete, water and an organic solvent can be added to the reaction system and mixed thoroughly. Then, organophosphorus R... 1 R 2 R 3 P dissolves in organic solvents to form an organic phase. The Li₂S, Na₂S, or K₂S produced in the reaction dissolve in water and undergo hydrolysis. Excess metals Li, Na, and K also react with water, and the hydrolysis products also dissolve in water, forming an aqueous phase. The organic and aqueous phases are then separated. The organic phase contains organophosphorus compounds R. 1 R 2 R 3 p and an organic solvent were reacted, and then the organic solvent was removed under reduced pressure to obtain organophosphorus R. 1 R 2 R 3 P.

[0045] The organic solvent can be the nonpolar hydrocarbon solvent described in this invention, or it can be a phosphine-sulfur compound R. 1 R 2 R 3 PS and organophosphorus R 1 R 2 R 3 P is soluble, but R 1 R 2 Other organic solvents insoluble in POX, and the metal reducing agent and divalent metal sulfide described in this invention are also insoluble in the organic solvents.

[0046] Due to organophosphorus R 1 R 2 R 3 P does not react with metals under nonpolar hydrocarbon solvent conditions; organophosphine R 1 R 2 R 3 P does not react with nonpolar hydrocarbon solvents, therefore phosphine sulfides R 1 R 2 R 3 When PS reacts with a metal reducing agent, the only product obtained is organophosphorus R. 1 R 2 R 3P and divalent sulfide metals, this reaction does not produce byproducts, and finally, phosphine sulfide compounds R 1 R 2 R 3 PS can react selectively with metal reducing agents to prepare organophosphorus compounds (R). 1 R 2 R 3 P.

[0047] This invention utilizes the reaction of phosphine oxides (R3PS) in phosphine-based compounds (R3P) with metals under nonpolar hydrocarbon solvent conditions to generate divalent metal sulfides insoluble in organic solvents and organophosphine compounds (R3P). 1 R 2 R 3 P is used to effectively remove phosphine oxides R3PS from phosphine-based compounds R3P.

[0048] This invention utilizes the phosphonooxide R3PO in the phosphono-based compound R3P and metal X under nonpolar hydrocarbon solvent conditions, wherein the phosphonooxide R3PO reacts with the metal to form a water-soluble salt R. 1 R 2 POX and R which are easy to evaporate 3 Series of organic compounds, R 1 R 2 PONa is insoluble in nonpolar hydrocarbon solvents but soluble in organic ethers. Phosphine compound R3P does not react with metal X or nonpolar solvents to form byproducts under nonpolar hydrocarbon solvent conditions. After the reaction is complete, a non-ether organic solvent and water are added to the reaction system. Phosphine compounds R3P and R... 3 A series of organic compounds dissolve in organic solvents to form an organic phase; water-soluble salts R 1 R 2 POX dissolves in water, and unreacted metal X reacts with water to form an aqueous phase. The organic phase and the aqueous phase are separated, and then R, which is easily evaporated from the organic phase, is removed. 3 By rotary evaporating a series of organic compounds, the phosphonooxide R3PO in the phosphono compound R3P can be removed, thereby achieving the purpose of purifying the phosphono compound R3P.

[0049] The following example uses metallic sodium to illustrate the reaction of phosphine oxide R3PO with metal X in a nonpolar hydrocarbon solvent, where phosphine oxide R3PO reacts with metal X to form a water-soluble salt R. 1 R 2 POX and R which are easy to evaporate 3 Further explanation of the series of organic compounds:

[0050]

[0051] Under an inert gas or nitrogen atmosphere, the phosphonium oxide compound R3PO reacts completely with metallic sodium in a nonpolar hydrocarbon solvent to produce R. 1 R 2 PONa and R 3 After the reaction of the compound was completed, the solid was filtered to obtain R. 1 R 2 PONa;

[0052] R3PO is R 1 R 2 R 3 PO, R 1 R 2 and R 3 Each is independently selected from aromatic or aliphatic substituents, with at least one being an aromatic substituent.

[0053] The following section uses Ph3PO as an example to further illustrate the conditions for the complete reaction of the phosphine oxide compound R3PO with metallic sodium in a nonpolar hydrocarbon solvent and under an inert gas or nitrogen atmosphere:

[0054] Under an inert gas or nitrogen atmosphere, Ph3PO reacts fully with metallic sodium in a nonpolar hydrocarbon solvent to produce Ph2PONa and Ph compounds. After the reaction is complete, the mixture is filtered to obtain a solid. The solid is dissolved in an ether organic solvent, filtered to remove insoluble matter, and the solvent and other volatiles are removed under reduced pressure to obtain a pale yellow solid Ph2PONa.

[0055] The above-mentioned solid is dissolved in an ether-based organic solvent, the insoluble matter is removed by filtration, and the solvent and other volatiles are removed by vacuum to obtain a pale yellow solid Ph2PONa; this operation step is to purify the solid Ph2PONa.

[0056] Since Ph2PONa, which is produced by the complete reaction of Ph3PO with metallic sodium, is insoluble in nonpolar hydrocarbon solvents, while the raw material Ph3PO and benzene compounds are soluble in nonpolar hydrocarbon solvents, Ph2PONa can be separated directly by filtration after the reaction is complete. Then, the separated solid Ph2PONa is dissolved in an ether organic solvent, filtered, evaporated under reduced pressure, and dried to obtain solid Ph2PONa.

[0057] Ph3PO reacts with metallic sodium under nonpolar hydrocarbon solvent conditions, and 1 mol of Ph3PO consumes only 1 mol of metallic Na.

[0058] Existing literature (Zhang, J. et al J.Org.Chem.2020, 85, 14166-14173) describes the reaction of Ph3PO with metallic sodium, which requires 2 mol of metallic Na to react with 1 mol of Ph3PO. This not only increases production costs, but also results in the decomposition of PhNa and the formation of sodium byproducts from the reaction of PhNa with the solvent. These sodium byproducts are difficult to separate effectively from the product Ph2PONa.

[0059]

[0060] PhNa reacts with solvents to form RONa, etc. RONa and Ph2PONa are difficult to separate and can only be used as a mixture.

[0061] The reaction mechanism of Ph3PO and metallic sodium under nonpolar hydrocarbon solvent conditions in this invention is as follows:

[0062]

[0063] Taking toluene as an example of the reaction solvent, Ph3PO reacts with metallic sodium under nonpolar hydrocarbon solvent conditions to form benzene free radicals. The reaction mechanism of benzene free radicals in this invention is as follows:

[0064] ①Ph· + Ph· → Ph - Ph;

[0065] ②Ph·+PhCh3→Ph-H+PhCh2·;

[0066] ③PhCh2·+PhCh2·→PhCh2-Ch2Ph.

[0067] Ph3PO reacts with metallic sodium in a nonpolar hydrocarbon solvent to generate Ph2PONa and form benzene radicals. After the formation of benzene radicals, the benzene radicals will combine with each other or react with the nonpolar hydrocarbon solvent to generate benzene compounds, instead of combining with metallic sodium to form PhNa.

[0068] The reaction mechanism of Ph3PO with metallic sodium described in existing literature (Zhang, J. et al J.Org.Chem. 2020, 85, 14166-14173) is as follows:

[0069] The reaction mechanism of the benzene radical described in existing literature (Zhang, J. et al J.Org.Chem. 2020, 85, 14166-14173) is as follows:

[0070] Ph· + Na → PhNa;

[0071] When benzene radicals combine with metallic sodium, they form PhNa. The PhNa reacts with the solvent to produce sodium compounds as byproducts, and PhNa also decomposes. Some of these byproducts dissolve in organic solvents. Some of these byproducts have similar properties to Ph2PONa, and when mixed with Ph2PONa, they are difficult to separate effectively and quickly. For example, RONa and Ph2PONa have similar properties and dissolve in the same solvent, making them difficult to separate effectively and quickly.

[0072] 3. Beneficial effects

[0073] Compared with the prior art, the advantages of this invention are:

[0074] (1) This invention uses phosphine-based compound R i R 2 R 3 Phosphooxides R in P 1 R 2 R 3 PO reacts with metal X in a nonpolar hydrocarbon solvent, wherein the phosphine oxide R 1 R 2 R 3 PO reacts with metallic X to form a water-soluble salt R. 1 R 2 POX and organic compounds that are easily evaporated under reduced pressure, phosphine compounds R 1 R 2 R 3 P does not react with nonpolar hydrocarbon solvents and metals under nonpolar hydrocarbon solvent conditions, through phosphine-based compounds R. 1 R 2 R 3 Based on the property that P is insoluble in water but soluble in organic solvents, a non-ether organic solvent and water are added to the reaction system. The organic and aqueous phases are separated, and then the organic compounds that are easily removed by rotary evaporation under reduced pressure are removed, thus eliminating the phosphine-based compound R. 1 R 2 R 3 Phosphooxides R in P 1 R 2 R 3 PO removal, thereby purifying the phosphine compound R 1 R 2 R 3 The purpose of P.

[0075] (2) This invention utilizes phosphine-based compound R 1 R 2 R 3 Phosphine sulfide compound R in P 1 R 2 R3 PS reacts with metals in a nonpolar hydrocarbon solvent, where the phosphine oxide R... 1 R 2 R 3 PS reacts with metal to produce R. 1 R 2 R 3 P and a divalent metal sulfide, after the reaction, utilize the divalent metal sulfide and the metal's insolubility in organic solvents, R 1 R 2 R 3 Given that P is soluble in organic solvents and that divalent metal sulfides and metal X are soluble in water, after the reaction is complete, the divalent metal sulfide is reacted with R. 1 R 2 R 3 p-separation can separate phosphine-based compounds R 1 R 2 R 3 Phosphine sulfide compounds R in P 1 R 2 R 3 PS removal, thereby purifying the phosphine-based compound R 1 R 2 R 3 The purpose of P.

[0076] (3) The purified phosphine compound R provided by this invention 1 R 2 R 3 The P method is simple, widely applicable, easy to operate, safe and controllable, and easy to scale up for industrial production. Detailed Implementation

[0077] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto:

[0078] Examples 1-14 and Comparative Example 1 relate to phosphine sulfide compound R 1 R 2 R 3 PS reacts fully with a metal reducing agent under nonpolar hydrocarbon solvent conditions and in an inert gas or nitrogen atmosphere to produce organophosphorus R. 1 R 2 R 3 P and divalent sulfide metals; no byproducts are generated during this preparation process, phosphine sulfide compounds R 1 R 2 R 3 PS can be used to selectively prepare organophosphorus R 1 R 2 R 3 P, Examples and Comparative Examples using metallic sodium as a reducing agent.

[0079] Example 1

[0080] 0.5 mmol of triphenylphosphine, 1.0 mmol of metallic sodium, and 1.5 mL of toluene were placed in a glass tube. The mixture was heated to 110 °C under nitrogen protection and reacted for 3 h. The mixture was then cooled to room temperature, the organic phase was washed twice with water, the organic solvent was removed under reduced pressure, and the mixture was purified to obtain 0.49 mmol of triphenylphosphine, with a yield of 98%.

[0081] Comparative Example 1

[0082] Other conditions were the same as in Example 1. The difference between Comparative Example 1 and Example 1 was that the polar solvent tetrahydrofuran was used as the solvent and the temperature was 70°C, resulting in 0.28 mmol Ph3P with a yield of 56% and containing 42% Ph2PH.

[0083] Example 2

[0084] 0.5 mmol of triphenylphosphine and 1.0 mmol of metallic sodium were placed in a glass tube, heated to 160 °C under nitrogen protection, and reacted for 3 h. The mixture was then cooled to room temperature, 3 mL of toluene was added, the organic phase was washed twice with water, the organic solvent was removed under reduced pressure, and the mixture was purified to obtain 0.3 mmol of triphenylphosphine, with a yield of 60%.

[0085] Example 3

[0086] 0.5 mmol of tris(p-methylphenyl)thionine, 1.0 mmol of metallic sodium, and 1.5 mL of toluene were placed in a glass tube. The mixture was heated to 110 °C under nitrogen protection and reacted for 3 h. The mixture was then cooled to room temperature, the organic phase was washed twice with water, the organic solvent was removed under reduced pressure, and the mixture was purified to obtain 0.48 mmol of tris(p-methylphenyl)thionine, with a yield of 96%.

[0087] Example 4

[0088] 0.5 mmol of tris(o-methylphenyl)thionine, 1.0 mmol of metallic sodium, and 1.5 mL of toluene were placed in a glass tube. The mixture was heated to 110 °C under nitrogen protection and reacted for 3 h. The mixture was then cooled to room temperature, the organic phase was washed twice with water, the organic solvent was removed under reduced pressure, and the mixture was purified to obtain 0.49 mmol of tris(o-methylphenyl)thionine, with a yield of 98%.

[0089] Example 5

[0090] 0.5 mmol diphenylmethylthiophosphine, 1.0 mmol metallic sodium, and 1.5 mL toluene were placed in a glass tube, heated to 110 °C under nitrogen protection, and reacted for 3 h. The mixture was then cooled to room temperature, the organic phase was washed twice with water, the organic solvent was removed under reduced pressure, and the mixture was purified to obtain 0.45 mmol diphenylmethylphosphine in 90% yield.

[0091] Example 6

[0092] 0.5 mmol phenyldimethylphosphine, 1.0 mmol sodium metal, and 1.5 mL toluene were placed in a glass tube, heated to 110 °C under nitrogen protection, and reacted for 3 h. The mixture was then cooled to room temperature, the organic phase was washed twice with water, the organic solvent was removed under reduced pressure, and the mixture was purified to obtain 0.48 mmol phenyldimethylphosphine, with a yield of 96%.

[0093] Examples 1-6 show that different phosphine sulfide compounds R 1 R 2 R 3 PS reacts with a metal reducing agent under solvent-free or nonpolar hydrocarbon solvent conditions to yield the corresponding organophosphine R. 1 R 2 R 3 P, and the yield is relatively high.

[0094] Example 7

[0095] Other conditions were the same as in Example 1. The difference between Example 7 and Example 1 was that 0.5 mmol of metallic sodium was used to react and 0.25 mmol of triphenylphosphine was obtained. The sodium-based yield was 100%.

[0096] Examples 1 and 7 show that when the metal reducing agent is sodium metal, sodium metal reacts with phosphine sulfide compound R. 1 R 2 R 3 When the molar ratio of PS is 1-2:1, sodium can react more fully with the reactants, further yielding phosphine sulfide compound R. 1 R 2 R 3 When PS reacts with a metal reducing agent, the metal reacts with the phosphine sulfide compound R. 1 R 2 R 3 The optimal molar ratio of PS is 1-2:1, which allows the metal reducing agent to react more fully and achieves a higher utilization rate.

[0097] Example 8

[0098] Other conditions were the same as in Example 1. The difference between Example 8 and Example 1 was that the reaction was carried out at 80°C for 10 hours to obtain 0.5 mmol of triphenylphosphine, with a yield of 100%.

[0099] Example 9

[0100] Other conditions were the same as in Example 1. The difference between Example 9 and Example 1 was that the reaction was carried out at 150°C for 2 hours to obtain 0.48 mmol of triphenylphosphine, with a yield of 96%.

[0101] As can be seen from Examples 1 and 8-9, the phosphine sulfide compound R provided by the present invention...1 R 2 R 3 When PS reacts with a metal reducing agent under solvent-free or non-polar hydrocarbon solvent conditions, organophosphorus R can be prepared at a temperature below 170°C. 1 R 2 R 3 p.

[0102] Example 10

[0103] Other conditions were the same as in Example 1. The difference between Example 10 and Example 1 was that Ph3PS with a purity of 85% (other main components of the raw material: 3% HOCH2CH2OH, 5% EtOH, 5% MeOCH2CH2OMe) was used to obtain 0.30 mmol of triphenylphosphine with a yield of 60%.

[0104] Example 10 shows that the phosphine-sulfur compound R reacts with a metal reducing agent under solvent-free or nonpolar hydrocarbon solvent conditions. 1 R 2 R 3 The purity of PS can be less than 100%.

[0105] Example 11

[0106] 0.5 mmol of triphenylphosphine, 1.0 mmol of metallic sodium, and 1.5 mL of ethylbenzene were placed in a glass tube. The mixture was heated to 136 °C under nitrogen protection and reacted for 3 h. The mixture was then cooled to room temperature, the organic phase was washed twice with water, the organic solvent was removed under reduced pressure, and the mixture was purified to obtain 0.45 mmol of triphenylphosphine, with a yield of 90%.

[0107] Example 12

[0108] Other conditions were the same as in Example 1. The difference between Example 12 and Example 1 was that p-xylene was used as the solvent to obtain 0.45 mmol of triphenylphosphine, with a yield of 90%.

[0109] Example 13

[0110] Other conditions were the same as in Example 1. The difference between Example 13 and Example 1 was that o-xylene was used as the solvent, yielding 0.46 mmol of triphenylphosphine in 92% yield.

[0111] Example 14

[0112] Other conditions were the same as in Example 1. The difference between Example 14 and Example 1 was that m-xylene was used as the solvent to obtain 0.45 mmol of triphenylphosphine, with a yield of 90%.

[0113] Examples 1, 1 Comparative Example, and 11-14 show that ethylbenzene, toluene, m-xylene, o-xylene, and p-xylene are all nonpolar hydrocarbon solvents, while tetrahydrofuran is a polar solvent; phosphine sulfide compounds R 1 R 2 R 3 PS reacts with a metal reducing agent under nonpolar hydrocarbon solvent conditions to form phosphine sulfide compound R. 1 R 2 R 3 PS can react with high selectivity to generate organophosphorus compounds (R). 1 R 2 R 3 P and divalent metal sulfides produce no byproducts; while phosphine sulfides R 1 R 2 R 3 When PS reacts with a metal reducing agent under polar solvent conditions, it produces a byproduct, a phosphine sulfide compound R. 1 R 2 R 3 PS cannot react with high selectivity to generate organophosphorus R. 1 R 2 R 3 P.

[0114] The following example uses the preparation of Ph2PONa from triphenylphosphine oxide to illustrate the process of phosphine-based compound R. 1 R 2 R 3 Phosphooxides R in P 1 R 2 R 3 PO reacts with metal X in a nonpolar hydrocarbon solvent, wherein the phosphine oxide R 1 R 2 R 3 PO reacts with metals to form salts R that are soluble in water and ether-based organic solvents. 1 R 2 POX and R which are easy to evaporate 3 Further description of the series of organic compounds:

[0115] Example 15

[0116] 0.5 mmol of triphenylphosphine oxide, 0.5 mmol of metallic sodium, and 2 mL of toluene were placed in a glass tube. The mixture was heated to 110 °C under nitrogen protection and reacted for 3 hours, then cooled to room temperature. The mixture was filtered under nitrogen to recover the solid. The obtained solid was placed in 5 mL of dry THF solvent and stirred at room temperature for half an hour. After filtration to remove insoluble matter, the solvent and other volatiles were removed under reduced pressure to obtain a pale yellow solid, Ph₂PONa, with a yield of 65%.

[0117] As can be seen from Example 15, the yield of phosphine oxide compound R is greater than 50%.1 R 2 R 3 The reaction of PO with metallic sodium in a nonpolar hydrocarbon solvent can reduce the amount of phosphine oxides (R). 1 R 2 R 3 PO reacts with metallic sodium to prepare R 1 R 2 PONa, one molecule of R 1 R 2 R 3 The technical problem of PO requiring the consumption of two molecules of metallic sodium is that the reaction products are easily separated from the reaction system after the reaction is complete, which can greatly reduce production costs.

[0118] Examples 16-24 below describe the preparation of Ph2PONa from triphenylphosphine oxide, followed by quenching of Ph2PONa after the reaction to prepare diphenylphosphine oxyhydrogen, and quantitative analysis of Ph2PONa using diphenylphosphine oxyhydrogen.

[0119] Example 16

[0120] 0.5 mmol of triphenylphosphine oxide, 0.5 mmol of metallic sodium, and 2 mL of toluene were placed in a glass tube. The mixture was heated to 110 °C under nitrogen protection and kept at this temperature for 3 h. After cooling to room temperature, a saturated NH4Cl aqueous solution was added. After the reaction was complete, 0.35 mmol of diphenylphosphine oxide was obtained, with a yield of 70%.

[0121] Example 17

[0122] In Example 15, under the same conditions, the reaction was carried out at 80 degrees Celsius for 3 hours to obtain 0.36 mmol of diphenylphosphine hydroxide, with a yield of 72%.

[0123] Example 18

[0124] In Example 15, under the same conditions, using ethylbenzene, 0.40 mmol of diphenylphosphine was obtained in 80% yield.

[0125] Example 19

[0126] In Example 15, under the same conditions, benzene was used and the reaction was carried out at 80 degrees Celsius for 3 hours to give 0.38 mmol of diphenylphosphine oxyhydrogen, with a yield of 77%.

[0127] Example 20

[0128] In Example 15, under the same conditions, ethylbenzene was used, and the reaction was carried out at 60 degrees Celsius for 3 hours to give 0.36 mmol of diphenylphosphine oxyhydrogen, with a yield of 72%.

[0129] Example 21

[0130] In Example 15, under the same conditions, ethylbenzene was used and the reaction was carried out at 60 degrees Celsius for 12 hours to give 0.38 mmol of diphenylphosphine oxyhydrogen, with a yield of 77%.

[0131] Example 22

[0132] In Example 15, under the same conditions, ethylbenzene was used, and the reaction was carried out at 130 degrees Celsius for 3 hours to give 0.35 mmol of diphenylphosphine oxyhydrogen, with a yield of 70%.

[0133] Example 23

[0134] In Example 15, under the same conditions, i-PrC6H5 was used, and the reaction was carried out at 110 degrees Celsius for 3 hours to obtain 0.37 mmol of diphenylphosphine oxyhydrogen, with a yield of 74%.

[0135] Example 24

[0136] In Example 15, under the same conditions, t-BuC6H5 was used, and the reaction was carried out at 110 degrees Celsius for 3 hours to obtain 0.36 mmol of diphenylphosphine oxyhydrogen, with a yield of 71%.

[0137] Examples 15-24 show that, under an inert gas or nitrogen atmosphere, phosphine oxide compound R... 1 R 2 R 3 The water-soluble salt R was prepared by reacting PO with metal X under different nonpolar hydrocarbon solvent conditions and at different temperatures. 1 R 2 POX and R which are easy to evaporate 3 A series of organic compounds, one molecule of R 1 R 2 R 3 The reaction of PO with metal X requires only one molecule of metal X. After the reaction is complete, the reaction products are easily separated from the reaction system, and the post-processing is simple.

[0138] Examples 25-33 illustrate the purification method for organophosphorus R provided by this invention. 1 R 2 R 3 Examples of purification of P impurities:

[0139] Example 25

[0140] Under a nitrogen atmosphere, a mixture of 1 mmol Ph3P and 0.05 mmol Ph3PO was placed in 5 mL of toluene solution, followed by the addition of 0.1 mmol of metallic sodium. The mixture was heated to 110 °C under nitrogen protection and reacted for 1 h. After cooling to room temperature, 2 mL of water was added, and the organic phase was washed twice with water. The solvent was removed under reduced pressure to obtain 1 mmol of triphenylphosphine with a purity >99.5%.

[0141] Example 26

[0142] Under a nitrogen atmosphere, a mixture of 1 mmol Ph3P and 0.05 mmol Ph3PS was placed in 5 mL of toluene solution, followed by the addition of 0.1 mmol of metallic sodium. The mixture was heated to 110 °C under nitrogen protection and reacted for 3 h. After cooling to room temperature, 2 mL of water was added, and the organic phase was washed twice with water. The solvent was removed under reduced pressure to obtain 1 mmol of triphenylphosphine with a purity >99.9%.

[0143] Example 27

[0144] Other conditions were the same as in Example 25. The difference between Example 27 and Example 25 was that 1 mmol Ph2PMe and 0.05 mmol Ph2P(0)Me were used for purification, and the reaction yielded 0.95 mmol Ph2PMe with a purity > 99.9%.

[0145] Example 28

[0146] Other conditions were the same as in Example 25. The difference between Example 28 and Example 25 was that 1 mmol Ph2PCH2Ph ​​and 0.05 mmol Ph2P(O)CH2Ph ​​were used for purification, and the reaction yielded 0.98 mmol Ph2PCH2Ph ​​with a purity > 99.9%.

[0147] Example 29

[0148] Other conditions were the same as in Example 25. The difference between Example 29 and Example 25 was that 1 mmol Ph2PMe and 0.05 mmol Ph2MeP(S) were used for purification, and the reaction yielded 0.99 mmol Ph2PMe with a purity > 99.9%.

[0149] Example 30

[0150] Other conditions were the same as in Example 25. The difference between Example 30 and Example 25 was that 0.1 mmol of lithium metal was used to react and obtain 0.99 mmol of triphenylphosphine with a purity > 99.3%.

[0151] Example 31

[0152] Other conditions were the same as in Example 25. The difference between Example 31 and Example 25 was that 0.1 mmol of metallic potassium was used to react and 0.98 mmol of triphenylphosphine was obtained with a purity > 99.5%.

[0153] Example 32

[0154] Other conditions were the same as in Example 25. The difference between Example 32 and Example 25 was that 5 mL of p-xylene was used to react and 0.98 mmol of triphenylphosphine was obtained with a purity > 99.9%.

[0155] Example 33

[0156] Other conditions were the same as in Example 25. The difference between Example 33 and Example 25 was that 5 mL of benzene was used to react and 1.0 mmol of triphenylphosphine was obtained with a purity > 99.5%.

[0157] As can be seen from Examples 25-33, the technical solution provided by the present invention can quickly and effectively treat substances containing R. 1 R 2 R 3 PO and / or R 1 R 2 R 3 organophosphine R of PS 1 R 2 R 3 The purification of P is easy to operate, safe and controllable, and the post-processing is simple. This purification method is easy to scale up for industrial production.

[0158] In addition to the embodiments described above, the present invention may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A method for purifying a phosphine-based compound, wherein the organophosphine R 1 R 2 R 3 P impurities are caused by organophosphorus R 1 R 2 R 3 The composition consists of P and impurities, the impurities including R. 1 R 2 R 3 PO and R 1 R 2 R 3 One or two arbitrary combinations of PS; where, R 1 R 2 and R 3 It can be independently selected from C1-C20 straight-chain or branched alkyl groups, C3-C20 cycloalkyl groups, C7-C20 aralkyl groups, C6-C20 aryl groups, or phenyl groups with C1-C6 long-chain or branched alkyl groups; R 1 R 2 and R 3 At least one of them is an aromatic substituent, said aromatic substituent being a C6-C20 aryl group or a C1-C6 long-chain or branched alkyl phenyl group; characterized in that: the method comprises the following steps: ； Step 1: Under an inert gas or nitrogen atmosphere, apply organophosphorus R... 1 R 2 R 3 Adding metal X and organophosphorus R to impurity P 1 R 2 R 3 Impurity P reacts fully with metal X under nonpolar hydrocarbon solvent conditions; The metal X is selected from one or any mixture of Li, Na and K; The reaction temperature is 60-180℃; Step 2: After the reaction is complete, use organophosphorus R 1 R 2 R 3 P is soluble in organic solvents but insoluble in water, R 1 R 2 Based on the properties that POX is soluble in water but insoluble in non-ether organic solvents, and X₂S is soluble in water but insoluble in organic solvents, and that metallic X is soluble in water but insoluble in organic solvents, the reaction products were separated by rotary evaporation under reduced pressure to remove the solvent and R. 3 The compound was obtained as an organophosphorus R. 1 R 2 R 3 P; In the method described above, when the organophosphorus R 1 R 2 R 3 Before adding metal to impurities P, organophosphorus R 1 R 2 R 3 Impurities P first dissolve in nonpolar hydrocarbon solvents; The nonpolar hydrocarbon solvent is selected from alkanes or aromatics; The molar ratio of the metal to the impurity is 0.1-5:

1.

2. The method for purifying phosphine-based compounds according to claim 1, characterized in that: Nonpolar hydrocarbon solvents and R 1 R 2 R 3 The weight ratio of impurities P is 0.5-20:

1.

3. The method for purifying phosphine-based compounds according to claim 1, characterized in that: The nonpolar hydrocarbon solvent is selected from one or any mixture of hexane, n-heptane, benzene, toluene, ethylbenzene, xylene, and trimethylbenzene.

4. The method for purifying phosphine-based compounds according to claim 1, characterized in that: The metal is selected from sodium.

5. The method for purifying phosphine-based compounds according to claim 1, characterized in that: The R 1 R 2 R 3 PO is Ph3PO, R 1 R 2 R 3 PS stands for Ph3PS, R 1 R 2 R 3 P is Ph3P.

6. The method for purifying phosphine-based compounds according to claim 1, characterized in that: The nonpolar hydrocarbon solvent is one or any mixture of toluene, ethylbenzene, benzene, xylene, and trimethylbenzene.

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